1. Field of the Invention
This invention relates to a tilt switch, more particularly to a tilt switch with an optoelectronic sensor member which is controlled by the displacement of a ball member to make or break electrical connection between two electric contact terminals.
2. Description of the Related Art
In the co-pending U.S. patent application Ser. No. 09/957,932, filed by the applicant, there is disclosed a tilt switch that includes light emitting and receiving units disposed in an insulating housing, a ball member received rollably in an accommodation chamber of the housing. When the housing is tilted, the ball member can roll between a first position and a second position so that a light beam emitting from the light emitting unit is permitted to be received by the light receiving unit or is blocked such that an optoelectronic switch can change from a first switch state to a second switch state.
The object of the present invention is to provide a tilt switch with a modular insert body that is replaceable to enable the tilt switch to have various degrees of sensitivity so as to be used for different kinds of electric apparatus.
According to this invention, the tilt switch includes a housing body adapted to be mounted on a support in an upright direction, and includes a top wall which extends in a longitudinal direction that is transverse to the upright direction, and which has a modular concavity extending downwardly, a bottom wall which has a bottom wall surface that confronts the concavity and that is spaced apart from the top wall by a modular depth, and right and left inner modular walls which are spaced apart from each other by a modular width to confine the concavity in the longitudinal direction, and which respectively have emitting and receiving slits that extend respectively therethrough in both the longitudinal and upright directions, and that are aligned with each other in the longitudinal direction to permit passage of a broader beam of light. Light emitting and receiving units are disposed in the housing body, and are respectively disposed rightwardly and leftwardly of the right and left inner modular walls to emit and to receive the broader beam of light that passes through. the emitting and receiving slits. A modular insert body includes entry and exit walls, and an inner peripheral wall. The entry and exit walls are opposite to and are distant from each other in the longitudinal direction by a modular thickness that is slightly smaller than the modular width. The entry wall has an entry hole which extends in the longitudinal direction and towards the exit wall, and which is configured to admit entry of only a portion of the broader beam of light into the entry hole, thereby forming a narrower beam of incident light in the entry hole so as to continue to pass through the receiving slit along a light path when the modular insert body is inserted into the concavity in the upright direction to contact the bottom wall surface of the bottom wall and when the entry and exit walls are brought to confront the right and left inner modular walls, respectively. The inner peripheral wall is disposed between the entry and exit walls to confine an accommodation chamber which extends in the longitudinal direction to communicate with the entry hole, and which ha a transit route that extends to intersect the light path at an intersection. A ball member is received in the accommodating chamber, is rollable across the intersection, and is displaceable from a first position where the housing body is steady in the upright direction, to a second position where the housing body is tilted relative to the upright direction. An optoelectronic sensor member is secured to the housing body, and includes two electric contact terminals which extend downwardly and outwardly of the housing body so as to be adapted to be connected electrically to the support, and an optoelectronic switch which electrically couples the electric contact to the light receiving unit such that the optoelectronic switch shifts from a first switch state to a second switch state when the ball member is lurched as a result of tilting to roll across the intersection from the first position to the second position, thereby interrupting or restoring the transmission of the narrower beam of incident light. A modular cover is configured to cover the modular concavity so as to prevent ambient light from entering thereinto.